Anatomy/Physio of Pain Flashcards
What processes result in noxious stimulus-inducing pain?
Transduction
Transmission
Modulation
Perception
How do nociceptors in the periphery respond to stimuli with regards to pain
-Nociceptors respond to intense heat, cold, mechanical or chemical stimuli –> encode intensity, location and duration of the noxious stimuli
What are the two primary somatosensory signaling channels?
- ) Anterolateral system: primary pain-signaling channel
2. ) Dorsal column/medial lemniscal: high-speed/discrete for innocuous stimuli
How is the dorsal horn arranged?
Anatomically into laminae
What fibers terminate in Rexed’s Laminae I/II in the dorsal horn?
Unmyelinated C fibers
What fibers terminate in Dorsal Horn Laminae III/V
Large Myelinated Fibers
Which part of the somatosensory system is the primary pain-signaling channel?
The anterolateral channel
What is the anterolateral channel composed of?
Anterolateral spinal tracts –> spinomedullary tract –> spinomesencephalic tract –> spinohypothalmic tract –> spinothalmic tracts
Where does the spinal dorsal horn tract terminate?
Medial Thalmus –> Cingulate Gyrus in the Cerebral Cortex
Where does the dorsal column/medial lemniscal tract terminate?
Lateral Thalmus –> Primary and Secondary Somatosensory Cortex within the Cerebral Cortex
What are the two types of second order nociceptive spinal and spinal trigeminal projection neurons?
1) Wide Dynamic Range
2) Nociceptive Specific
What fibers provide input to Wide Dynamic Range cells?
AB and nociceptive (C and AD) fibers
What is the the primary pain-signaling channel?
Anterolateral system
What is the high-speed discrete signaling channel for innocuous stimuli
Dorsal column-medial lemniscal
What cortical areas (known as the pain matrix) are involved in acute and chronic pain?
- Primary and secondary somatosensory cortices
- Insula
- Anterior cingulate cortex
- Prefrontal cortex
- Amygdala
- Nuclei of the thalamus
